In many packet-oriented communications networks, such as the Internet, no Quality of Service is guaranteed for connections between terminals in these communications networks unless additional arrangements are made. The Quality of Service (QoS) of a connection may include different transmission and connection resources, such as the transmission bandwidth, transmission rate, permissible error rate and/or transmission duration.
In modern communication systems, which are frequently based on packet-oriented communications networks of this kind, so-called resource managers are provided to ensure a specified Quality of Service. These are in each case assigned to a communications network or subnetwork and administer its relevant transmission resources. With a resource manager, pre-definable transmission resources can be reserved for each specific connection to be set up. When transmission resources have been successfully reserved, the resource manager monitors the continuous availability of the reserved transmission resources for the relevant connection.
In many cases, connections must be established between different subnetworks of a communication system, the subnetworks themselves having a very high transmission bandwidth, but being interconnected by one or more individual transmission links with relatively low transmission bandwidth. A typical example of this is Local Area Networks (LANs) which are interconnected via a public telephone network. The telephone network with its relatively low transmission bandwidth in this case constitutes a bottleneck for data interchange between the LANs.
The problem often arises that the transmission resources of such a bottleneck are usually exhausted by even a relatively small number of connections having a resource requirement that is typical of a subnetwork with high transmission bandwidth. This generally results in a relatively high rejection rate for connections to be routed via the bottleneck.